Some of the best Raspberry Pi projects are those that seem so simple, in hindsight, but which it takes a particular type of brain to envisage. Take this Raspberry Pi Compute Module 4 conversion from MBS or Magic Blue Smoke, on Hackaday.
Simply by inverting the usual Raspberry Pi 4 HDMI connection, and expanding it to normal size, you can turn the module into a TV stick, ready for action in anything with an HDMI port without an adapter or cable. Load up the on-board MMC with RetroPie or Kodi, and you’ve got the perfect stick to carry with you to hotels and friends’ houses where you’re likely to need entertainment.
The HDMI plug is on a carrier board, which cradles the Compute Module and adds a USB-C port for power, and two USB 2 sockets - one of which would be great for adding an IR remote. There’s a microSD card slot (see best Raspberry Pi microSD cards), a switch for enabling the CM4’s USB device mode, and a mysterious User Button, the purpose of which is not immediately clear. MBS is clearly a talented hacker, but not particularly verbose in his or her descriptions.
There also appear to be two versions of the device, one with the USB ports held vertically, and another with them horizontally. They both hold the CM4 in the same way, but there are slight differences in the heat sinks used for passive cooling. GPIO access is left available for hacking new bits onto the board.